Production of metallic catalysts



' UN TED- STATES ,nnnn'sr rosnrn nusn, on LONDON, ENGLAND, ASSIGNOR mo TECHNICAL nnsnancn PATENT oFFI CE; I

-WORKS LIMITED, LONDON, ENGLAND frnonucrron or rinrannlc 'oa'rar.vsrs. o

in Drawing. Application filed May 11, 1925 Serial 1%. 29,617, and in-Great Britain July 16, 1924.

This invention relates to improvements in I I the 'method of activating-and reactivating' metallic catalysts by subjecting the surfaces of the metal forming the base to 'an electrolytic anodic, oxidationdn an electrolytic bath using as electrolyte a salt which will not allow the metal to pass into solution with the result that on' passage of the electric current an activeprecipitate is coated over the metal-which is subsequently washed, dried and reduced in-Yhydrogenwhereb'y a very active formof catalyst is produced. The present invention has particular refer- .ence to the preparation or production of a catalyst or catalysts suitable for use in the .manufacture of synthetic ammonia or prod ucts usedtherein, for example, hydrogen or a is not rcmoved'by washlng but the catalyst hydrogen in the 7 knownother purposes.

It is. Well knownthat in the manufacture so of catalysts for use in catalytic reactions e;.-g.

' the manufacture of'synthetic ammonia or hydrogen comparatively large pieces of iron oxide or other ore serve the purpose of the catalytic mass used in the process, and the ob'ject'of the present invention is to produce "a catalytic mass. of higher efliciency for the purpose o thatv less room is occupied for a given production.

I have found hat when a metal, for example,v iron, in the form of turnings, plates 1 or ribbon-likeproducts is subjected to surface oxidation as above described and treated in a similar: manner a very active catalyst is producedsuitable, for example,

for the synthesis of ammonia from nitrogenand. hydrogen mixtures or hydrogen, fromcarbon monoxide and water vapour mixtures.

Further when an alloy of two or more metals'is to be used as catalyst, for-example,

0 nickel and'copper in the hydrogenatioli'of oils or dehydrogenation of alcohols or other purposes for which vcatalysts are used,'.the above'de'sc'ribed process of catalyst manufacture' is especially applicable since the composition of the surface which has been oxidized and reduced very closely approxt: mates tothat of the unoxidized alloy, and

"mate 'icontact therewith,- and therefore-on reduction a catalyst is produced containing the metals ofthe original alloy ,very intimately mixed, andin approximately thesame proportions.

When it is desired to produce a cataylst be made from iron turnings oxidized anodi cally in an electrolytic bath' containing potassium carbonate or hydroxide in solution." I. In this latter case the alkali salt remaining on theturnings after removal from the hath reduced by manner;

'Morcover since the catalyst is readily reactivated,without loss of electrolyte, use canbe made-of the rare alkalies more economically than heretofore." v

What I claim is I faces and i;estoring' such activity in spent catalysts, which consists in subjecting the 1. The method of activating metallic surmetallic'surfaces to an electrolytical anodic,

oxidation using as the electrolyte anaqueous solution of a saltof an alkali metal, which salt will. not allow the metal of said surfaces to pass into solution, whereby the metal on.

oxidation contains the adsorbed salt in intis ducing inl hydro'gen'.

2.-The method of I faces and restoring such activity in spent catalysts, which consists in subjecting iron turnings to an electrolytical anodic ox'idation using as the electrolyte an aqueous so-,

l-ution of potassium carbonate, and after-- wards reducing the oxidized surfaces of the afterwards re activatin metallic surturnings inhydrogen, whereby ayery active catalyst is produced. I In testimony, whereof I aflEix m signaturc.

ERNEST J QSEP 

